@article{fdi:010094303,
  title = {{P}etrogenetic processes in alkaline magmatism in the southern {M}ozambique {C}hannel},
  author = {{B}erthod, {C}. and {B}ach{\`e}lery, {P}. and {R}evillon, {S}. and {D}oucelance, {R}. and {S}chiavi, {F}ederica and {D}evidal, {J}. {L}. and {B}ou, {E}. and {J}orry, {S}. {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}hereas the northern part of the {M}ozambique {C}hannel, between the eastern coast of {A}frica and {M}adagascar, is intensively studied, the southern part remains poorly investigated. {T}he 2014 {PAMELA}-{MOZ}01 and 2015 {PAMELA}-{MOZ}04 cruises enabled us to collect volcanic rocks from the submarine flanks of the {B}assas da {I}ndia{E}uropa complex, including {B}assas da {I}ndia atoll, {E}uropa {I}sland, and {J}aguar and {H}all {B}anks. {D}espite significant alteration, probably due to their prolonged stay in seawater and the hydrothermal circulation they underwent, we are able to describe the main petrological and geochemical aspects of these largely unknown lavas. {T}o achieve this, we integrated petrographic and mineralogical observations with geochemical analyses of the dredged rocks, aiming to identify the key aspects of the alteration and to characterize their petrological and geochemical properties. {T}he volcanism of this region is characterized by strongly silica-undersaturated alkaline magmas. {H}ere, we demonstrate that this volcanism is marked by a bimodal magmatic activity with ultrabasic and basic compositions, and more silica-rich compositions. {U}sing isotopic signatures and trace elements, we suggest that magmas are produced by a low degree of partial melting (1 to 5 %) of a metasomatized mantle at about 80 km depth. {T}hese mafic magmas then rise from the source to the surface via several magma storage levels, located at about 25-30 km and 15 km depth, the latter corresponding to the mantle-crust boundary as identified by geophysical methods. {F}ragments of zoned sanidine phenocrysts within intermediate lavas (olivine-free nephelinite or tephriphonolite) also suggest the presence of differentiated magma reservoirs. {O}ur observations strongly support frequent magmatic recharges, coupled with magma differentiation through olivine + clinopyroxene crystallization/assimilation, in long-lived magma reservoirs. {I}n many respects, this volcanism has similar characteristics (nature of the source, degree of partial melting, composition of the lavas, age, and spatial distribution) to those of the {M}iocene to {Q}uaternary volcanic provinces of {M}adagascar, the northern {M}ozambique {C}hannel or the {E}ast {A}frican {R}ift. {W}e propose that this volcanism might result from regional extension through the {M}ozambique {C}hannel and the southern part of the {E}ast {A}frican {R}ift {S}ystem, coupled with a thermal erosion of a mantle plume.},
  keywords = {{M}ozambique {C}hannel ; {V}olcanism ; {S}eamounts ; {P}etrology ; {E}uropa and {B}assas ; da {I}ndia ; {OCEAN} {INDIEN} ; {MOZAMBIQUE} {CANAL}},
  booktitle = {},
  journal = {{L}ithos},
  volume = {512},
  numero = {},
  pages = {108155 [20 p.]},
  ISSN = {0024-4937},
  year = {2025},
  DOI = {10.1016/j.lithos.2025.108155},
  URL = {https://www.documentation.ird.fr/hor/fdi:010094303},
}